﻿/*
 *  ====================================================================
 *    Licensed to the Apache Software Foundation (ASF) under one or more
 *    contributor license agreements.  See the NOTICE file distributed with
 *    this work for additional information regarding copyright ownership.
 *    The ASF licenses this file to You under the Apache License, Version 2.0
 *    (the "License"); you may not use this file except in compliance with
 *    the License.  You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 * ====================================================================
 */

namespace NPOI.SS.UserModel.Charts
{
    public interface IChartDataSource<T>
    {
        /**
        * Return number of points contained by data source.
        *
        * @return number of points contained by data source
        */
        int PointCount { get; }

        /**
         * Returns point value at specified index.
         *
         * @param index index to value from
         * @return point value at specified index.
         * @throws {@code IndexOutOfBoundsException} if index
         *                parameter not in range {@code 0 &lt;= index &lt;= pointCount}
         */
        T GetPointAt(int index);

        /**
         * Returns {@code true} if charts data source is valid cell range.
         *
         * @return {@code true} if charts data source is valid cell range
         */
        bool IsReference { get; }

        /**
         * Returns {@code true} if data source points should be treated as numbers.
         *
         * @return {@code true} if data source points should be treated as numbers
         */
        bool IsNumeric { get; }

        /**
         * Returns formula representation of the data source. It is only applicable
         * for data source that is valid cell range.
         *
         * @return formula representation of the data source
         * @throws {@code UnsupportedOperationException} if the data source is not a
         *                reference.
         */
        string FormulaString { get; }
    }
}